Railway-gate



UNITED STATES PATENT OFFICE.,

ALEXANDER J. MODONALD, OF CHICAGO, ILLINOIS.

RAiLWAY-GATE.,

SPECIPICATION orning part of Letters Patent No. 383,969, dated June 5, J 888.

Application filed December G, '1887. Serial No. 52573094. (No model.)

TO all whom it may cocern:

Be itknown that I, ALEXANDER J. MCDON- ALD,Of Chicago, Illinois,have invented certain new and useful Improvements in Railway- Gates,of which the following is a specification.

The object of my invention is to secure increased efficiency in the operation of said gates; and my improvements and inventions consist in the means whereby this object is attained, as hereinafterpointed out and claimed.

The princi pal feature ofmy presentinprovement relates to the connections between the piston-rod of the engine usually employed in these gates and the gatearms.

In the drawings, Figurelis a side elevation of a gate-arm and its supporting-post, the latter being partly in section, and containing the cylinder (also in section) with its pisten, piston-rod, and connections between the pisten rod and arn. Fig. 2 isa section taken online 2 2 of Fig. 1; and F'g. 3 is a transverse vertical section through the'lower part of the post, showing the cylinder, its air-supply pipes, its piston-rod, and a modified Construction of the connections of said rod. i

The stationary supporting post or case Ais preferabl y made of iron. lt is hollow and contains the noving parts. It has an extension, B,on its front side to receive the cylinder, and such extension has a hinged cap or cover, b, which can be thrown back to permit access to the cylinder.

C is the cylinder. It has the compressed airsupply pipes cc', communicating with its interier near each end, respectively. A piston, D, is fittcd to the cylinder and reciprocates therein under the pressure of the com-` pressed air supplied by pipes c c'.

E is the piston-rod, which nay have rackteeth e formed on its outer end. It is supported byan anti-friction roller, f, carried by a standard, F, or other suitable guide or support. The connecting means between the gatearm and the piston-rod comprise two links, G G, pivoted at their lower ends to a cross-bar, H, and at their upper ends to a cross-bar, I. The bar H is fixed at it's middle to a rockshaft, J, and the bar I is likewise fixed to the rock-shaft K, upon which the gate-arm is seeured. The rock-shefi; J earries a toothed sector, L,whose teeth en mesh with the raek-teeth e of the piston-rod E. The reciprocation of the piston-rod operates by the above-described means to raise and lower the gatearms.

A modified construetion of the connections between the piston-rod and the rock-shaft J is shown in Fig. 3. In said figure a fixed arm, M, depends from the rock-shaft J, and a link, N, pivoted, respectively, to the end of the piston-rod and said arni, transmits motion to the rock-shalt.

Of course modifications of the Construction herein shown and described may be made.

Thelength of the cross-ba-I of the links G and the sector L or corresponding connections may be varied. I prefer to make said links rigid, in order that both, when connected to the piston-rod, may be acted upon by the latter, and thercby both made to act upon the pivoted gate-bnr.

I claim- 1. The combination, in a railway-gate, ofa pivoted gatebar, a cross-beam Secured to and turning with the gateba', a powencylinden located toward the bottom of the gatepost and having a horizontally-reciprocating pis ton-red, a rock-shaft having Secured thereto a second cross-beam, suitable connectng devices between the piston-rod and said rock-shaft, Whcreby the latter is roeked, and links' connecting said erossbeams on both sides of their eenters of oscillation, substantially as described.

2. The combination, in a railway-gate, of a gate-bar pivoted upon a rockshaft, a crossbeam Secured to said roek-shaft, a power-cylinder having a horizontally-reciprocating piston-red provided with a rack, a segment secured upon a second rock-shalt and adapted to be operated by the piston, a cross-benin secured to said last-named rock-shalt, and links` connecting said cross-beams on both sides of their'centers of oscillation, suhstantially as lVitnesses:

G. C. LINTHICUBL D. H. J ACKMAN. 

